Rotation speed control system and control method

ABSTRACT

A rotation speed control system of a fan includes a blade group, a motor driving the blade group to rotate, a temperature sensing unit and a controlling unit. The temperature sensing unit is configured to sense a temperature of a local environment of the fan. The controlling unit is configured to control the motor to rotate at a speed according to the sensed temperature of the local environment and a relationship between the temperature and a motor speed. The disclosure also provides a rotation speed control method of a fan.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Taiwan Patent Application No. 201410701841.5, filed on Nov. 28, 2014, the contents of which are incorporated by reference herein.

FIELD

The subject matter herein generally relates to a rotation speed control system and control method of a fan.

BACKGROUND

In high temperature environments a fan can be used for cooling.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.

FIG. 1 is a block diagram of a fan rotation speed control system.

FIG. 2 is a flowchart of a fan rotation speed control method.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.

The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series, and the like.

FIG. 1 illustrates a rotation speed control system of a fan 10 includes a blade group 12, a motor 14, a storage unit 16, a switch unit 18, a temperature sensing unit 20 and a controlling unit 22. The rotation speed control system of the fan 10 is configured to automatically adjust a rotation speed of the blade group 12 according to a temperature of a local environment of the fan 10.

The storage unit 16 is configured to store a relationship between a temperature and a motor speed. The temperature in the relationship is from 28 to 36. The motor speed in the relationship is from 500 revolutions per minute to 1500 revolutions per minute. High temperature is corresponding to high motor speed.

The switch unit 18 is configured to control the fan 10 to turn on and turn off. The temperature sensing unit 20 is configured to sense the temperature of the local environment when the fan 10 is turned on. The temperature sensing unit 20 may be a circuit including a thermistor. A resistance of the thermistor is increased with a rise of the temperature. When the resistance is changed, an output voltage of the circuit is changed. The temperature sensing unit 20 obtains the temperature of the environment according to the output voltage. In the embodiment, the temperature sensing unit 20 periodically senses the temperature of the environment according to a preset period, for example, two hours. In another embodiment, the temperature sensing unit 20 senses the temperature of the environment in real time.

The controlling unit 22 is configured to control the motor 14 to rotate in a speed corresponding to the sensed temperature according to the sensed temperature and the relationship. The motor 14 is configured to drive the blade group 12 to rotate.

In the embodiment, the temperature in the relationship includes a preset critical temperature, for example, 25. The controlling unit 22 is further configured to control the switch unit 18 to turn the fan 10 off when the temperature of the environment is below the preset critical temperature. Therefore, the fan 10 turns off when the temperature of the environment is below the preset critical temperature.

The control system of rotation speed of a fan 10 further includes a display unit 24. The display unit 24 is configured to display the current temperature of the environment.

Referring to FIG. 2, a flowchart is presented in accordance with an example embodiment. The example method is provided by way of example, as there are a variety of ways to carry out the method. The method described below can be carried out using the configurations illustrated in FIG. 1, for example, and various elements of these figures are referenced in explaining example method. Each block shown in FIG. 2 represents one or more processes, methods or subroutines, carried out in the example method. Furthermore, the illustrated order of blocks is illustrative only and the order of the blocks can change according to the present disclosure. Additional blocks can be added or fewer blocks may be utilized, without departing from this disclosure. The example method can begin at block 102.

At block 102, the temperature sensing unit 20 senses the temperature of the environment where the fan 10 is located when the fan 10 is activated. In the embodiment, the temperature sensing unit 20 periodically senses the temperature of the environment according to a preset period, for example, two hours. In another embodiment, the temperature sensing unit 20 senses the temperature of the environment in real time.

At block 104, the controlling unit 22 controls the motor 14 of the fan 10 to rotate at a speed according to the sensed temperature of the local environment and a relationship between a temperature and a motor speed. The temperature in the relationship is from 28 to 36. The motor speed in the relationship is from 500 revolutions per minute (RPM) to 1500 RPM. High temperature is corresponding to high motor speed.

At block 106, the motor 14 drives the blade group 12 to rotate.

In another embodiment, the flowchart of a control method of a rotation speed of a fan 10 further includes block 108 and block 110.

At block 108, the display unit 24 displays the sensed temperature of the environment.

At block 110, the controlling unit 22 turns off the fan 10 when the temperature of the environment is below a preset critical temperature, for example, 25.

The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the details, including in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including, the full extent established by the broad general meaning of the terms used in the claims. 

What is claimed is:
 1. A rotation speed control system of a fan comprising: a storage unit storing a relationship between a temperature and a motor speed; a temperature sensing unit sensing a temperature of a local environment of the fan when the fan is activated; a motor; a controlling unit controlling the motor to rotate at a speed according to the sensed temperature of the local environment and the relationship between the temperature and the motor speed; and a blade group driven to rotate by the motor.
 2. The rotation speed control system of a fan as claimed in claim 1, wherein the temperature sensing unit periodically senses the temperature of the environment according to a preset period.
 3. The rotation speed control system of a fan as claimed in claim 2, wherein the preset period is two hours.
 4. The rotation speed control system of a fan as claimed in claim 1, wherein the temperature sensing unit senses the temperature of the environment in real time.
 5. The rotation speed control system of a fan as claimed in claim 1, wherein the temperature in the relationship comprises a preset critical temperature, the controlling unit further controls the fan to turn off when the temperature of the environment is below the preset critical temperature.
 6. The rotation speed control system of a fan as claimed in claim 5, wherein the preset critical temperature is
 25. 7. The rotation speed control system of a fan as claimed in claim 1, further comprising a display unit, the display unit displaying the sensed temperature of the environment.
 8. The rotation speed control system of a fan as claimed in claim 1, wherein the temperature in the relationship is from 28-36.
 9. The rotation speed control system of a fan as claimed in claim 1, wherein the motor speed in the relationship is from 500 revolutions per minute to 1500 revolutions per minute.
 10. The rotation speed control system of a fan as claimed in claim 1, wherein high temperature is corresponding to high motor speed.
 11. A rotation speed control method of a fan comprising: sensing a temperature of the environment where the fan is located when the fan is activated; controlling a motor of the fan to rotate at a speed according to the sensed temperature of the local environment and a relationship between a temperature and a motor speed; and driving the blade group to rotate by the motor.
 12. The rotation speed control method of a fan as claimed in claim 11, wherein periodically senses the temperature of the environment according to a preset period.
 13. The rotation speed control method of a fan as claimed in claim 12, wherein the preset period is two hours.
 14. The rotation speed control method of a fan as claimed in claim 11, wherein senses the temperature of the environment in real time.
 15. The rotation speed control method of a fan as claimed in claim 11, wherein the temperature in the relationship comprises a preset critical temperature.
 16. The rotation speed control method of a fan as claimed in claim 15, further comprising: controlling the fan to turn off when the temperature of the environment is below the preset critical temperature.
 17. The rotation speed control method of a fan as claimed in claim 15, wherein the preset critical temperature is
 25. 18. The rotation speed control method of a fan as claimed in claim 11, further comprising: displaying the sensed temperature of the environment.
 19. The rotation speed control method of a fan as claimed in claim 11, wherein in the relationship, high temperature is corresponding to high motor speed.
 20. The rotation speed control method of a fan as claimed in claim 11, wherein the temperature in the relationship is from 28 to
 36. 